Diamond Bar High: High scores, healthy climate, strong attendance. We looked for a catch — we didn't find one.
Diamond Bar posts 46.3% exceeding the standard — versus 15.8% statewide — with climate numbers better than most. That doesn't make it perfect. It makes it worth a visit to find what numbers can't measure.
| Scope | % Exceeded | % Met+ | Grad rate | College readiness | Absence | Suspension | |
|---|---|---|---|---|---|---|---|
| This school | 74 | 46% | 72% | 95.8% | 91.2% | 10.8% | 1.0% |
| CA average · High School | 44 | 16% | 36% | 87.6% | 35.4% | 30.2% | 3.6% |
Diamond Bar High scores 74 of 100 on SchoolScope's Scope Score — the 97th percentile of 2,160 California high schools (CDE CAASPP 2025).
Measures test performance, attendance, and climate — not arts, community, or your kid. How we score →
💪 Strong All-Around — Ask about what we don't score — class size, electives, the feel of a classroom — strong numbers everywhere on paper don't mean every classroom feels the same.
Most rating sites would stop at “72% proficient” and call it done. Diamond Bar deserves a closer read. It sits at the 97th percentile of 2,160 California high schools — but the ranking is the least interesting thing on this page.
Diamond Bar's low-income kids hit 69.4% proficiency in ELA — a number the same group reaches at 38.2% statewide. If you're trying to read past zip-code-driven test scores, that's the signal worth weighing.
The seven-year arc
Has held the 97th-percentile line every tested year since 2019.
This school hasn't fully recovered from the pandemic: 72% meet the standard today, versus 77% in 2019 — a gap worth asking about on a visit.
| Grade | 2019 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Grade 11 | 80% | 78% | 79% | 78% | 76% |
| Grade | 2019 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Grade 11 | 73% | 70% | 68% | 67% | 68% |
The story this school is actually telling
Of 100 students here: 72 are proficient by 11th grade → 96 graduate → 91 pass an AP exam. The gaps between those bars are the questions to ask.
Diamond Bar's most underrated number
69.4% of low-income students met the ELA standard — versus 38.2% for the same group statewide. That's the strongest kind of signal a school can post: it holds across income lines.
The 7 things our score weighs
Ask what the school is working on next. Strong numbers tell you where a school is, not where it's going.
- Ask whether extra support — tutoring, counseling, small groups — reaches kids across income lines, not just the students already ahead.
- Ask whether the tour can step into a working classroom — watch how the teacher handles a student who's stuck.
- Ask to tour while school's in session, and notice how hallways and transitions feel — culture shows up between classes, not just in them.
- Ask how the school communicates with families when a child starts to struggle.
- Ask what a typical day looks like for a new student in the first few weeks.
How every group of students does here
At Diamond Bar High in Diamond Bar, 69.4% of low-income students met or exceeded the ELA standard in 2025, compared to 67.5% district-wide and 38.2% statewide. Diamond Bar High outperforms its district average for low-income students by 1.9 percentage points in ELA. Other subgroups: Low-Income students (62.3% Math proficient); Asian students (82.4% ELA proficient). The largest proficiency gap is 71.2 percentage points for english learner students. Data source: California Department of Education, CAASPP 2024-25. 158 students tested.
Showing up, and staying in class
Where the path goes
The path below follows attendance boundaries — scores shown for each next step.
Feeder patterns derived from NCES attendance boundary data. Boundaries are approximate and may have changed — verify with your school district for current assignments.
The people teaching here
Pay is set by the district, not the school.
What gets spent here
$275 per student arrives as federal Title funding — a measure of concentrated need, not school quality.
The district's current expense of education per student, from CDE's annual SACS filing — the freshest district spending figure the state publishes.
District-level, from the district's own SACS general-ledger filing — school-by-school breakdowns aren't published by the state.
Source: NCES F-33 · Full district breakdown →
The neighborhood it serves
Source: U.S. Census Bureau, American Community Survey 5-year estimates (2024) · ZIP-level
At 2,563 students, this school is well above the typical California high school (≈1450).
On the state's science test (CAST), 54% met or exceeded the standard — science is tested in grades 5 and 8 but never enters the Scope Score.
Frequently asked questions
Is Diamond Bar High a good high school?
What are Diamond Bar High's CAASPP test scores?
How does Diamond Bar High rank in California?
What is the attendance and school culture like at Diamond Bar High?
How does Diamond Bar High compare to other schools in Diamond Bar?
How does Diamond Bar High serve low-income and underrepresented students?
Your other options
Nearby Elementary Schools
3 within ~3 mi · avg 74
Nearby Middle Schools
2 within ~3 mi · avg 80
Private alternatives nearby
Private schools within ~10 miles. These schools do not participate in state testing and cannot be scored or ranked.
Every number on this page
Score factors, grade-level breakdowns, subgroup proficiency, and peer comparisons.
| ELA | Tested | EXC | MET | NEAR | NOT | MET+ | +/CA |
|---|---|---|---|---|---|---|---|
| Grade 11 | 625 | 48% | 28% | 13% | 11% | 76% | +29 |
| Math | Tested | EXC | MET | NEAR | NOT | MET+ | +/CA |
|---|---|---|---|---|---|---|---|
| Grade 11 | 622 | 44% | 24% | 16% | 16% | 68% | +45 |
| Science (CAST) | Tested | EXC | MET | NEAR | NOT |
|---|---|---|---|---|---|
| Grade 5/8/11 | 597 | 18% | 36% | 42% | 5% |
CAST is tested in grades 5, 8, and once in high school — not annually. Not part of the Scope Score.
| Subgroup · ELA | Tested | MET+ | vs district | vs CA |
|---|---|---|---|---|
| Socioeconomically Disadvantaged | 158 | 69.4% | +2 | +31 |
| Asian | 415 | 82.4% | +1 | +8 |
| Hispanic/Latino | 107 | 52.8% | −5 | +14 |
| School | Dist | Scope | EXC | MET+ | Growth | Susp |
|---|---|---|---|---|---|---|
| Diamond Bar High ← | — | 74 | 46.3% | 72.3% | — | 1.0% |
| Walnut High | 2.7 mi | 72 | 47.0% | 71.6% | — | 1.3% |
| California average | — | 44 | 15.8% | 35.7% | — | 3.6% |
| Year | Scope | Pctile | Rank | Exc | Met+ | Absent | Susp | Growth |
|---|---|---|---|---|---|---|---|---|
| 2019 | 79 | 97 | #53 | 49.8% | 76.6% | 6.7% | 2.7% | — |
| 2022 | 75 | 97 | #59 | 46.0% | 74.2% | 10.9% | 2.6% | — |
| 2023 | 75 | 97 | #57 | 46.2% | 73.7% | 10.6% | 2.3% | — |
| 2024 | 73 | 97 | #68 | 43.3% | 72.3% | 10.4% | 2.4% | — |
| 2025 | 74 | 97 | #68 | 46.3% | 72.3% | 10.8% | 1.0% | — |
| Group | 2019 | 2025 | Δ |
|---|---|---|---|
| Female | 6.6% | 10.1% | +3.5pp |
| Male | 6.0% | 10.6% | +4.6pp |
| Asian | 4.0% | 6.9% | +2.9pp |
| Black/African American | 13.3% | 11.1% | -2.2pp |
| White | 5.9% | 8.2% | +2.3pp |
| Hispanic/Latino | 11.5% | 20.9% | +9.4pp |
| Two or More Races | 9.5% | 12.9% | +3.4pp |
| Students with Disabilities | 16.4% | 23.5% | +7.1pp |
| English Learners | 9.7% | 7.5% | -2.2pp |
| Socioeconomically Disadvantaged | 9.0% | 15.4% | +6.4pp |
| All Students | 6.3% | 10.3% | +4.0pp |
| Pacific Islander | — | 36.4% | — |
SchoolScope scores and verdicts are our interpretation of public California Department of Education data — independent analysis, not an official rating. How we analyze · Request a correction